Food and exercise tips for people with type one diabetes

Written by: Dr David Cavan
Edited by: Bronwen Griffiths

Dr David Cavan is a leading diabetes physician with expertise in the management of type one diabetes. Here he dispels myths surrounding what foods type one diabetic patients can and cannot eat, as well as tips for exercising.

What food myths should people with type one diabetes be aware of?

There are a number of myths that circulate which can be really quite confusing for someone with type one diabetes.

  1. The first one is probably not really a myth, because it was standard advice at one point, but I think it is now a myth. This myth is the idea that you should base all your meals on carbohydrates and that you should eat carbohydrates regularly throughout the day. Carbohydrates are the foods that make your blood glucose level go up, so constantly feeding your system with carbohydrates through the day is not always a good idea.
  2. The second myth is that you can pretty much eat whatever you like. Actually, some people take that to heart and they do eat whatever they like, including meals that are high in sugar and high in carbohydrates. But what does that do? Well, what it does is it pushes their blood glucose level up to quite high levels. That then needs to be corrected by extra doses of insulin; which sometimes can then go the opposite way in causing lower levels. Hence, if you have been told that then I have to say I would consider that the myth.

However, when it comes to choosing what foods to eat, I would never say never. If there are certain foods that you want to eat once in a while, then enjoy them, but know that it will cause your blood glucose level to rise. As a rule, I would recommend keeping an eye on your diet and putting some control over it, especially over the carbohydrates that you eat.

What exercise do you recommend for people with type one diabetes?

Exercise is very important for all of us whether we have diabetes or not. For someone with type one diabetes, however, it does cause some issues that need to be taken care of. This is because of what exercise will do to affect the level of glucose in your blood. That is why it is important to be aware of that and of the effect of the particular exercise you do on your blood glucose level.

There are no specific forms of exercise that I recommend for diabetic patients as any exercise is good, but as I said, it is important to ensure that each person with type one diabetes understands how it affects their glucose level.

So what effects could they have? Exercise requires the body to use more energy because the muscles are pumping away and they need glucose in order to help them do that. Therefore, quite commonly what people will see if they exercise is that their blood glucose level will reduce. That usually means that you need to reduce the amount of insulin you are injecting in order to make sure you don't go too low. On the other hand, certain other types of exercise could cause a blood glucose level to rise and this is something a number of people find quite a surprise.

An aerobic activity such as lifting weights cause glucose levels to rise because of the adrenaline that is produced. Additionally, intensive bursts of activity such as sprints can also increase glucose levels.

Therefore, what I say to people with diabetes is: do the exercise that you really enjoy, but you need to do a little bit of work to help work out how you can best enjoy it without it adversely affecting your blood glucose levels.


To learn more about diet and exercise in relation to type one diabetes, make an appointment with an expert.

By Dr David Cavan
Endocrinology, diabetes & metabolism

Dr David Cavan is one of the UK's leading diabetes physicians with considerable experience and expertise in all aspects of the management of the condition. He has particular interest in the intensive management of type 1 diabetes including insulin pump therapy, and lifestyle management in those with type 2 diabetes.

Dr Cavan strongly believes in the importance education and self-management for people with diabetes, and he has developed educational programmes for those with type 1 & 2 diabetes. He has worked on a number of global projects, including most recently the development of programmes in Bermuda to tackle the high prevalence of type 2 diabetes there. 

Dr Cavan has contributed to numerous peer-reviewed publications on many aspects of diabetes. In 2014, he published his first book, 'Reverse your diabetes: the step by step plan to take control of type 2 diabetes'. This was followed in 2016 by 'Reverse your diabetes diet'. In 2018 he published two books, 'Take control of type 1 diabetes' and, together with food writer Emma Porter, 'The low carb diabetes cookbook'.   

He consults at London Medical on Wednesday afternoons.  Please call to book an appointment.  Alternatively, he is available for e-consultations via Topdoctors. Please note that the private messaging function is not suitable for detailed advice and should only be used as a follow up to a face to face or e-consultation.

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